Field of the Invention
The present invention relates to a thermosensitive adhesive label excellent in printability and satisfying both excellent anti-blocking property after printing and excellent peelability from the object with the label stuck thereto.
Description of the Related Art
These days much used are plastic containers such as polyethylene terephthalate (PET) bottles for sale of water, refreshing drinks, etc; and a label printed with the trade name, the design and the information data relating to the contents thereof is often stuck to such containers. For the label, used is a known pressure-sensitive adhesive label, or proposed is a thermosensitive adhesive label (delayed label) in which the back of the substrate sheet is coated with a thermosensitive adhesive agent not adhesive at room temperature (10 to 30° C.) and the opposite face thereof is printed (e.g., JP-B 5-18433, and JP-A 1-22290, 6-100847, 6-100848, 7-319390, 8-76690).
The thermosensitive adhesive label of the type becomes adhesive when the adhesive layer part thereof is heated while the label is stuck to a container, and therefore, before use, it is not adhesive and has the advantage of storability with no use of release paper indispensable for pressure-sensitive adhesive labels. Once the thermosensitive adhesive exhibits adhesiveness by heating, it may keep the adhesiveness for a given length of time even after the heating is stopped, and therefore has the advantage of especially excellent sticking stability.
However, the thermosensitive adhesive label is stored generally as a roll, and especially in summer, it becomes adhesive during storage and therefore causes a problem of blocking. To solve the problem, proposed is a method of adding an anti-blocking additive to the adhesive agent for the thermosensitive adhesive label to thereby make the label have an anti-blocking property, or a thermosensitive adhesive prepared with a plasticizer or a lubricant added thereto (e.g., JP-A 6-179855, JP-B 62-21835).
However, the label with the adhesive to which the above-mentioned additive is added has problems in that the adhesion strength thereof is low and the paste may remain on the object after peeling of the label from it since the adhesive layer strength is low.